Fiber connector and adapter

ABSTRACT

Fiberoptic connector and adapter assembly includes a fiberoptic connector received within an adapter. The connector has a cover on the connector housing. The cover pivots between open and closed positions to expose or cover, respectively, a optical fiber contained within the connector. Longitudinal guides of the connector are received cooperating with longitudinal guides of the adapter to direct the connector into the adapter in a prescribed alignment. A cam pin is carried on the adapter to engage a cam pin receiving slot on the cover to urge the cover to the open position as the connector is inserted into the adapter.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation of application Ser. No. 11/092,317,filed Mar. 29, 2005, now U.S. Pat. No. 7,118,288; which is acontinuation of application Ser. No. 10/213,350, filed Aug. 5, 2002; nowU.S. Pat. No. 6,910,807, which is a continuation of application Ser. No.09/921,526, filed Aug. 3, 2001, now U.S. Pat. 6,471,416; which is acontinuation of application Ser. No. 09/583,681, filed May 30, 2000, nowU.S. Pat. No. 6,296,398; which is a continuation of application Ser. No.09/394,303, filed Sep. 10, 1999, now U.S. Pat. No. 6,076,973; which is acontinuation of Ser. No. 09/207,838, filed Dec. 8, 1998, now U.S. Pat.No. 5,984,531; which is a continuation of application Ser. No.08/859,533, filed May 20, 1997, now U.S. Pat. No. 5,883,995; whichapplications are incorporated herein by reference.

I. BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention pertains to connectors and adapters for optical fibers.More particularly, this invention pertains to such connectors andadapters which include end caps for covering an end of the connector oradapter when the connector is not inserted into a mating adapter.

2. Description of the Prior Art

Fiberoptic connectors historically presented exposed ends. Further,adapters which received such connectors presented exposed interiorelements. The exposed ends and interior elements included the terminalends of optical fibers. As a result, such terminal ends would besusceptible to impact damage or the like. Further, light transmittedthrough the optical fiber could inadvertently be directed into the eyeof a technician or other person viewing the optical fiber or adapter.

The prior art has developed end caps for covering optical fibers when aconnector is not in use. An example of such is shown in U.S. Pat. No.5,348,487 to Marazzi et al dated Sep. 20, 1994. FIGS. 5 and 6 of the'487 patent illustrate two types of end caps which are pivoted to anopen position as the end cap is placed within an adapter. FIGS. 7 and 8illustrate an embodiment where a end cap 6 is pivoted to an openposition and then slid rearwardly to expose a ferrule 5. An adapter forthe connector is shown in FIG. 9. The adapter includes both an externalhousing 16 and an internal housing 15. The internal housing 15 includesa slot 30 which receives a pin 29 of the end cap 6. The slot 30 causesboth the pivoting and the sliding action of the end cap 6 as theconnector is placed within the adapter. Furthermore, the adapterincludes an internal door 32 (shown in FIG. 10) which covers internalferrules 2 when a connector 1 is removed from the adapter. Uponplacement of a connector 1 into the adapter, the end cap is pivoted andslid to an open position and the door is pivoted to an open position.Further examples of such structures are found in U.S. Pat. Nos.5,420,951 and 5,363,460. These patents show fiberoptic connectors to bejoined in adapters. While not SC adapters, the adapters shown in thesepatents are sized to have cross-sectional profile (i.e., footprint) thesame as so-called SC adapters. An SC adapter is shown in commonlyassigned U.S. Pat. No. 5,317,663.

SC adapters are standard industry adapters having a fixed external sizeand geometry. The structure of the aforementioned '951, '487 and '460patents provide end caps and internal doors for the purpose of blockinglight or protecting elements in connectors. However, the manner in whichsuch functions are achieved restricts the density of fiberopticconnectors. Namely, in those patents, only single pairs of connectorsmay be optically coupled within a single adapter. Within the industry,it is desirable to provide up to two pairs of connectors being opticallycoupled in a single adapter. It is an object of the present invention toprovide protective covering and doors for connectors and adapters in astructure that permits two connectors pairs to be coupled in an adapterhaving the same size as a standard size SC adapter.

II. SUMMARY OF THE INVENTION

According to preferred embodiment of the present invention, a fiberopticconnector and adapter assembly comprises a fiberoptic connector with anoptical fiber disposed within the connector housing. A cover is carriedon the connector housing and pivots between an open and a closedposition. In the closed position the cover closes an opening of theconnector housing. In an open position, the cover exposes the opening.The connector housing includes a longitudinal guide aligned with alongitudinal axis of the connector housing. The cover further includes acam pin receiving-slot. The adapter includes an adapter housing sized toreceive the connector housing. A fiber coupling mechanism is containedwithin the interior of the adapter to align with an optical fiber of aninserted connector. The adapter housing further includes a longitudinalguide which cooperates with the longitudinal connector guide to directthe connector into axial alignment with the adapter fiber couplingmechanism. The adapter housing further includes a cam pin disposedwithin the interior to be received within the cam pin receiving slot tourge the cover from a closed position to an open position as theconnector housing is inserted into the adapter housing.

III. BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a connector/adapter assembly includingan SC adapter containing two pairs of optically coupled connectors;

FIG. 2 is an end elevation view of the connector/adapter assembly ofFIG. 1;

FIG. 3 is a view taken along line 3—3 of FIG. 2;

FIG. 4 is a view taken along line 4—4 of FIG. 3;

FIG. 5 is a front, top and side perspective view of the connector usedin the assembly of FIG. 1 with an end cap shown in an open position;

FIG. 6 is the view of FIG. 5 with the end cap shown in the closedposition;

FIG. 7 is an exploded perspective view of the connector of FIG. 5;

FIG. 8 is a front elevation view of the connector of FIG. 6;

FIG. 9 is a view taken along line 9—9 of FIG. 8;

FIG. 10 is a view similar to that of FIG. 5 showing an alternativeembodiment of a connector which contains a ferrule;

FIG. 11 is the view of FIG. 10 with an end cap in an open position;

FIG. 12 is an end elevation view of the connector of FIG. 11;

FIG. 13 is a view taken along line 13—13 of FIG. 12;

FIG. 14 is an exploded perspective view of the connector of FIG. 10;

FIG. 15 is the view of FIG. 3 with an alternative embodiment connectorand adapter;

FIG. 16 is a view taken along line 16—16 of FIG. 15;

FIG. 17 is a perspective view of the adapter of the assembly of FIG. 1;

FIG. 18 is an end elevation view of the adapter of FIG. 17 with one doorshown in a closed position;

FIG. 19 is a view taken along line 19—19 of FIG. 18;

FIG. 20 is a view taken along line 20—20 of FIG. 19;

FIG. 21 is the view of FIG. 19 showing an alternative embodimentadapter;

FIG. 22 is a view taken along line 22—22 of FIG. 21;

FIG. 23 is a side elevation view with internal elements shown in phantomlines of a connector of FIG. 11 being initially inserted into an adapterof FIG. 21;

FIG. 24 is the view of FIG. 23 showing additional insertion of theconnector to a point where an end cap is about to pivot toward an openposition;

FIG. 25 is the view of FIG. 24 showing still further insertion of theconnector to a point where an internal door of the adapter is shown inthe fully open position and the end cap is not yet to a fully openposition;

FIG. 26 is the view of FIG. 25 showing still further insertion where thedoor is about halfway pivoted; and

FIG. 27 is the view of FIG. 26 showing yet further insertion of theconnector into the adapter with both the door of the adapter and the endcap of the connector shown in fully open positions.

IV. DESCRIPTION OF THE PREFERRED EMBODIMENT

With initial reference to FIGS. 1–4, a connector/adapter assembly 10 isshown including four fiberoptic connectors 12 (each of identicalconstruction) contained within a single adapter 14. The externalgeometry of the adapter 14 is the same as that shown in U.S. Pat. No.5,317,663. In other words, the cross is sectional area of the adapter 14is identical to that of a standard SC adapter such as that shown in U.S.Pat. No. 5,317,663 so that the adapter 14 may be inserted intopreexisting applications which received the prior SC adapter of U.S.Pat. No. 5,317,663.

The adapter 14 is separately shown in FIGS. 17–20 to which attention isnow directed. The adapter 14 includes two halves 16, 16′ joined at aflange 18. The flange 18 may be placed within a sheet metal support sothat multiple adapters 14 can be positioned in side-by-side alignment ona sheet metal panel. Preferably, when the halves 16, 16′ are joined, thepart line between the halves 16, 16′ is ultrasonically welded so thatthe halves 16, 16′ form an inseparable and solid adapter 14.

The top and bottom walls 20, 21 and sidewalls 36 of the adapter definean adapter housing having an longitudinal axis X-X. The adapter 14presents a generally rectangular cross section perpendicular to axis X-Xand including a major transverse axis Y-Y and a minor transverse axisZ-Z. An interior wall 22 extends along the longitudinal axis X-X andperpendicular to the major transverse axis Y-Y. The wall 22 divides theinterior of the adapter housing into first and second chamber pairs 24,24 a and 24′, 24 a′. Connectors inserted within opposing chambers 24, 24a are optically coupled. Similarly connectors inserted into opposingchambers 24′, 24 a′ are optically coupled.

The chambers 24, 24′ are separated from the opposing chambers 24 a, 24a′ by interior wall segment 26 containing fiber coupling mechanisms 28,28′. In the embodiments of FIGS. 17–20 the fiber coupling mechanism 28,28′ is a micro capillary sleeve 29, 29′ contained within a cylindricalhousing 31, 31′. The micro capillary sleeves 29, 29′ have internal bores30, 30′ for receiving an optical fiber. The micro capillary sleeves 29,29′ are aligned with their axes being parallel to the longitudinal axisX-X and centrally positioned (relative to the major transverse axis Y-Y)within the chambers 24, 24′. The micro capillary sleeve includes areservoir 35, 35′ for receiving an index matching fluid to provide indexmatching between opposing optical fibers inserted into bores 30, 30′. AnO-ring 53, 53′ surrounds the exterior of the cylindrical housing 31, 31′at wall 26. The O-ring 53, 53′ is sized with an outer diameter greaterthan a diameter of a forward opening 58 (FIG. 5) of the connector 12.

The use of micro capillary sleeves 29, 29′ contained within the adapter14 is for use with so-called ferruleless connectors such as those shownin FIGS. 1–4. It will be appreciated that the present invention is alsoapplicable to connectors which contain ferrules. In such an embodiment,the fiber coupling mechanism 28 is not a micro capillary sleeve but willinclude a split sleeve 29 a, 29 a′ for receiving ferrules contained onthe connectors. Such an embodiment is illustrated in FIGS. 21–22.

Doors 38 are pivotally secured to the upper wall 20 to pivot between anopen position (shown on right hand side of the adapter in FIG. 18) and aclosed position (shown on the left hand side of FIG. 18). The doors 38are sized such that in the closed position, the doors 38 block directvisual inspection through the open ends of the adapter 14 to the fibercoupling mechanisms 28. As a result, in an event a fiberoptic connectoris connected to one side of the fiber coupling mechanism 28 (e.g., theright side of FIG. 12), the closed door 38 on the opposite sidesprevents a technician from looking directly at light on the oppositeside of the fiber coupling mechanism 28. The doors 38 are spring loadedto the closed position shown in FIG. 38 by springs 39. Stop posts 40contained on opposing interior surfaces of the walls 36, 22 limit themovement of the doors 38 past the open position.

The adapter 14 also includes longitudinal adapter guides 42, 42′ in theform of longitudinally extending rails which extend parallel to thelongitudinal axis X-X in close proximity to the lower wall 21. At theopen ends of the adapter 14, the upper wall 20 is provided withinternally extending protrusions 44 for the purpose of locking aconnector in place as will be described. Also, the opposing interiorsurfaces of the walls 36, 22 include cam pins 46 for purposes that willbe described. The doors 38 included cut out sides such that as the door38 pivots to the closed position, the door 38 is free to pass both thecam pins 46 and the longitudinal adapter guides 42.

With reference to FIGS. 5–9, the connector 12 includes an outerconnector housing So. The connector 50 has a is longitudinal axis X′-X′and a front end 52 having a major transverse axis Y′-Y′ and minortransverse axis Z′-Z′ (FIG. 8). The major transverse axis Y′-Y′ extendsfrom a base wall 54 to a top edge 56. The front end 52 includes aconnector opening 58 through which a terminal end of an optical fiber 60extends. The optical fiber 60 is an extension of an optical fibercarried in an optical cable 62 connected to the connector 12.

Within connector 12, the fiber 60 passes through a mandrel 51 and acrimp 57 to define two crimp zones for crimping on the cable'sreinforced fiber (not shown) and internal 9 mm fiber 63. A strain reliefboot 65 surrounds the mandrel 51 and cable 62. The interior of thehousing 50 includes an internal cavity 67 (FIG. 9) to permit smallamounts of displacement of fiber 60 as opposing fibers butt within themicro capillary sleeves 29 as opposing connectors 12 are opticallycoupled.

To increase return loss, the fiber 60 is angularly cleaved. Whenopposing fibers 60 are mated in the index matching fluid within microcapillary sleeves 29, 29′, the angular mating surfaces can be slightlyoverlapped (for example, by several microns). The mechanical stressinduced by connecting optical fibers can be reduced by the elasticproperties of the fiber 60 accommodated by cavity 67.

The hole 58 at front end 52 is an entrance to a cylindrical chamber 69(FIG. 9) sized in close tolerance to the outer diameter of the adapter'scylindrical housing 31. An O-ring 55 is contained within chamber 69.O-ring 55 is sized with an outside diameter greater than the internaldiameter of chamber 69. The inside diameter of O-ring 53 is smaller thanthe outside diameter of cylindrical housing 31. The outside diameter ofO-ring 53 is greater than the diameter of opening 55. As shown in FIGS.3 and 4, when connector 12 is fully inserted, O-ring 53 is squeezed intoopening 58. At the same time, O-ring 55 is squeezed. The O-rings 53, 55keep any moisture or water from penetrating the optical coupling. Withreference to FIGS. 3 and 4, it will be appreciated that O-rings 53, 55cooperate to provide circumferential and axial seals.

The housing 50 is sized to be received within any one of chambers 24, 24a, 24′, 24 a′ of the adapter 14. The connector 12 includes alongitudinal connector guide in the form of longitudinally extendingslots 64 on opposite sides of the connector housing 50. The slots 64 areparallel to the longitudinal axis X′-X′ and are spaced from the lowerwall 54. The slots 64 are positioned to receive the guide rails 42, 42′when the connector 12 is inserted into the adapter 14 with the base 54abutting the lower wall 21 and with the major transverse axis Y′-Y′ ofthe connector 12 in parallel alignment with the minor transverse axisZ-Z of the adapter 14.

A cover 66 is pivotally secured to the connector housing 50 to pivotabout an axis Z″-Z″ of which is parallel to axis Z′-Z′ and spacedrearwardly of the front face 52. FIG. 5 shows the cover 66 in an openposition exposing the opening 58 and the fiber 60. FIG. 6 shows theconnector 12 with the cover 66 pivoted to a closed position closing theopening 58 and covering the fiber 60.

The cover 66 includes a cam pin receiving slot 68 positioned at the axisZ″-Z″. As will be more fully described, the slot 68 is positioned toreceive the pin 46 when the cover 66 is in the closed position as theconnector 12 is inserted into the adapter 14. The pin 46 rotates thecover 66 to the open position at which point the pin 46 exits the slot68 upon further insertion. Removal of the connector 12 from the adapter14 reverses the action so that the pin 46 causes the cover 66 to pivotto the closed position.

As shown in FIG. 7, the housing 50 includes two detents 70, 72. Thecover 66 includes a pin 74. The detents 70, 72 and pin 74 are mutuallypositioned such that the pin 74 is received within the detent 72 whenthe cover 66 is in the closed position. The pin 74 is received withinthe detent 70 when the cover 66 is in the open position. Positioning ofthe pin 74 within the detents 70, 72 acts to hold the cover 66 in afixed position (i.e., either held in an open or closed position).

The edge 56 includes a forwardly protruding cam surface 76 and a cut outportion 78. The cam portion 76 is disposed to engage the cover 38 as theconnector 12 is inserted into the adapter 14. The cut out 78 is sized toreceive the pivoted cover 66 when the connector 12 is fully insertedinto adapter 14 and the cover 66 is in a full open position.

With prior art connectors, latches have been provided to secure aconnector to an adapter. However, such latches commonly included voidsinto which fibers could migrate and become caught or lodged. The presentinvention utilizes a connecting clip 80 having a free end 82 and an end84 secured to the housing So. The free end 82 is positioned between thefront end 52 and the end 84 such that the cantilevered clip 80 pointsforwardly. The clip 80 includes a ramp surface 86 at the free end 82 toengage the protruding ledges 44 of adapter 14 when fully inserted.Depression of the clip 80 frees the ramp edge 86 from the ledges 44 sothat the connector 12 can be removed.

The rails 42 are received within the slots 64 to guide and direct theconnector 12 in the desired direction of travel along axis X′-X′. Thefree end 82 includes a cutout to permit the free end 82 to pass the edge56 in close tolerance (indicated by spacing 83 in FIG. 9) such thatopposing surfaces of the edge 56 and free end 82 are separated by aspacing 83 smaller than the diameter of the cable 62. Accordingly, cable62 cannot migrate inadvertently into the volume 85 (FIG. 9) definedbetween the opposing surfaces of the connector housing 50 and the clip80.

With the construction thus described, two connectors 12 may be placedside by side into an adapter 14. As a result, the connectors 12 may beindividually moved or inserted. From time to time, it may be desirableto couple adjacent connectors 12 so that they are simultaneouslyinserted or removed. A coupling clip 100 (FIGS. 1–4)is provided. Theclip 100 includes a body portion 102 sized to match a spacing betweenadjacent connector housings 50 and configured to mate with the opposingsurfaces of the connector housings 50. Pins 104 (FIG. 4) protrude fromthe body 102 and project into holes 105 (FIG. 5) in the connectorhousings 50. The clip 100 further includes a cap 107 to span the uppersurfaces of the adjacent connectors 12. As a result, the spacer 100securely connects two connectors 12 so that they may be removed orinserted simultaneously. It will be appreciated that the spacer 100 isoptional to permit connectors 12 to be individually or simultaneouslyremoved or replaced at the option of a technician.

With the structure thus described, two connectors 12 may be placed in anadapter 14 having the same footprint of an SC adapter of prior artconstruction. Further, both of the connectors 12 include pivoting endcaps 66 for covering the fiber 60 contained within the connector. Theadapter 14 includes a pivoting door 38 for covering internal opticalcomponents and shielding such components from the eye of a technician.

The foregoing description pertains to a ferruleless connector 12 andmating adapter 14. The invention is also applicable to aferrule-containing connector 12′ and mating adapter 14′. These areillustrated in FIGS. 10–21. Elements of this embodiment in common withthe first described embodiment are not separately described and areidentically numbered with the addition of an apostrophe to distinguishthe embodiments.

The connector 12′ is separately shown in FIGS. 10–14. The adapter 14′ isshown in FIGS. 21 and 22. FIGS. 15 and 16 show an assembly of theconnector 12′ and adapter 14′.

Unlike the connector 12, connector 12′ contains a ferrule 13′ axiallypositioned in chaffer 69′ and protruding beyond the front end 52′. Theferrule 13′ is contained within a hub 15′ biased from a mandrel 51′ by aspring 17′. The fiber 60′ passes through the ferrule 13′. The adapter14′ contains a split sleeve 29 a, 29 a′ to receive ferrules 13′ andalign opposing ferrules 13′ and fibers 60′ in axial alignment. In allother material respects, connector 12 and 12′ and adapters 14, 14′ areidentical.

The sequence of operation of the device is best illustrated in FIGS.23–27. In the embodiment shown in FIGS. 23–27, a connector 12′containing an internal ferrule 13 (such as that shown in FIG. 13) isshown being inserted into an adapter 14′.

In FIG. 23, the connector 12′ is first inserted into the adapter 14′.The cover 66′ is in the closed position and has moved the door 38′ tocause the door 38′ to pivot. The pin 46 is not yet received in thy slot68′. FIG. 24 shows further insertion where the pin 46 is just receivedin slot 68′ but is not yet causing the connector cover 66′ to pivot. Thecam 76′ is positioned to engage door 38′.

Upon further insertion, the view of FIG. 25 is attained where the camedge 76′ is engaging the door 38′ to cause the door to pivot to an openposition such that the cover 66′ is free for pivotal movement. At thispoint, the pin 46′ is urging against the slot surfaces 68′ to cause thecover 66′ to pivot. As the cover 66′ pivots, the pin 74′ moves out ofthe detent 72′.

Still further insertion is illustrated in FIG. 26 where the cam edge 76′retains the door 38′ in the open position and where the cover 66′ is notyet at a full open position but the ferrule 13′ is exposed and alignedwith the coupling mechanism 28′. At this point, the cover 66′ is halfwaythrough its full rotational movement as illustrated by the pin 74′ beinghalfway between the detents 70′, 72′.

FIG. 27 shows still further insertion where the cover 66′ has been movedto its full open position with the pin 74′ received within the detent70′ and with the cover 66′ snugly received within the detent 78′.Further insertion of the connector 12′ at this point causes the ferrule13′ to be passed into the fiber coupling mechanism 28 and for the clipramp surface 86′ to slide under and be captured by the retaining edges44′. Upon depression of the clip 80′, the connector 12′ can be removedreversing the sequence of operation and causing the pin 46′ to rotatethe cover 66′ to the fully down position. The spring 39 causes the door38′ to pivot to a closed position.

The foregoing details of the description of the present inventionillustrates how the novel combination of novel connector and adapterachieve the functions of a cover of the end of the connector and a doorwithin the adapter as well as permitting a design which permits twoconnectors to be fitted in side-by-side relation in a single SC adapterhaving the same cross sectional area as prior art SC adapters.Accordingly, the density is doubled over the density of prior artconnectors having covers such as those shown in the aforementioned U.S.Pat. No. 5,363,460.

1. A method of assembling a fiber optic connector, the method comprisingthe steps of: a) providing a one-piece housing defining an interiorchamber and an interior cavity; b) providing an optical cable assemblyincluding a mandrel, a hub, a ferrule, and an optical cable having anoptical fiber, the optical cable extending through the mandrel and thehub, the optical fiber of the optical cable extending through theferrule, the ferrule being contained by the hub; c) inserting theoptical cable assembly into the housing, including: i) locating portionsof the ferrule within each of the interior chamber and the interiorcavity of the housing; ii) positioning a spring within the interiorcavity of the housing to bias the hub of the optical cable assemblytoward the interior chamber of the housing; and iii) inserting a portionof the mandrel into the interior cavity of the housing and biasing thespring such that a terminal end of the optical fiber extends through anopening in a leading end of the one-piece housing; and d) securing theoptical cable assembly in relation to the one-piece housing.
 2. Themethod of claim 1, wherein the step of securing the optical cableassembly in relation to the one-piece housing includes crimping a crimppositioned about the mandrel.
 3. The method of claim 2, wherein the stepof crimping includes crimping the crimp in two crimp zones to secure theoptical cable assembly in relation to the one-piece housing.
 4. Themethod of claim 1, further including surrounding a portion of themandrel and a portion of the optical cable with a strain relief boot. 5.The method of claim 1, further including attaching a pivoting cover tothe leading end of the one-piece housing, the cover being positionablein an open position to expose the terminal end of the optical fiber, anda closed position to cover the terminal end of the optical fiber.
 6. Themethod of claim 1, further including angularly cleaving the opticalfiber of the optical cable.
 7. The method of claim 1, wherein the stepof locating portions of the ferrule within the housing includespositioning the ferrule such that an end of the ferrule protrudes beyondthe leading end of the housing.